Of Rooftops and Cats (And the Imperfect Science of Falling in Love)
by FirePyr
Summary: You're my best friend, my human diary, and my other half. You mean the world to me, and I love you.
1. Adrien

**Author's Note:** A sorta prequel to a fanfiction I'm thinking of writing titled You Can't Con Yourself, in which instead of being superheroes, Ladybug and Chat Noir are con artists and thieves in a kind of Heist Society AU. In this AU, Adrien and Marinette met each other young and grew up with each other, running on rooftops and slowing falling in love with their best friend, no matter how much they try to deny it.

* * *

 **1.** **Adrien**

ADRIEN AGRESTE HAD ALWAYS BEEN AN UNUSUAL CHILD.

From a young age, this fact was apparent. He was loud and energetic and had a knack for finding trouble and a smile for everyone, which didn't fit well in the Agreste line of quiet children and stern faces. He had his mother's blond hair and green eyes and his father's strong features but his character was most entirely his late grandmother's, as was his unique ability to model and meet any photographer's expectations.

To put it simply, he was a dream to work with in more than one way.

At the age of four, he was on the front cover of the Gabriel© magazines and on the catwalk at five. His smiles lined the streets of Paris, and his name was known throughout the fashion industry by the time his sixth birthday came about.

The world adored him, and his family shunned him.

Perhaps it would have been different if his grandmother had not passed on, for they shared the same type of soul. Or perhaps it wouldn't have made a difference anyway. But the past cannot be changed, and Adrien Agreste grew up in a world of fake smiles and double meanings.

He was the black sheep of the Agreste family, and yet it was still a surprise when he grew tired of pretending to be someone he wasn't and started living up to the name.

He began to skip photoshoots and meetings. He found out he could fit into the role of bad boy just as well as he could the role of model son, although to be honest, there was a _lot_ of things frowned upon by the Agreste family. The world ate it up, if possible, loving him even more (it didn't hurt matters that he looked good in leather).

Maybe this change in characteristics was a cry for help, for attention, but it wouldn't have worked anyway because, not long after this change, they looked at him and deemed him a lost cause and _stopped caring_.

Adrien Agreste had the best money could offer and yet, he longed for the one thing money couldn't buy: love.

When he was eight, he began to take on more dangerous exploits and clambered onto the roof of the Agreste Mansion armed with a rope and his telescope to see the stars.

Not that anyone knew about it, of course.

But it did spark a fire that would burn in him forever.

The next time he gave his bodyguards the slip and skipped a photoshoot, he climbed on the fire escapes and realized no one ever looked up. From that moment on, his favorite mode of travel was by roof. Soon after, he discovered that the best time to run across the rooftops of Paris was at night, when streetlights lit a glow under his feet and the city quieted.

About a month later, he found and adopted a cat, much to his parents' disapproval. But Plagg was allowed to stay, and Adrien toned down his exploits for a while, although his midnight runs didn't lessen in number.

And then, one night, Plagg suddenly shot out the window with a yowl that threatened to wake the entire mansion up, perching on the roof and blinking at Adrien and refusing to leave even when Adrien took out the camembert. He had climbed after the darned cat, just to have Plagg dash down into the garden using the ivy on the walls and window ledges. Not for the first time, he wondered why he kept the cat in the first place, for Plagg was lazy and had an unfortunate addiction to camembert that stunk his room to the high heavens.

Thus began a midnight chase that had Adrien growing steadily frustrated as the night wore on and the cat kept just out of his reach. He was just about to admit defeat when he turned a corner and immediately smacked foreheads with someone else, both of them tumbling down on the dusty roof.

When he had rubbed his forehead enough and found it in himself to blink past the pain and open his eyes, he was met with a pair of the biggest bluebell eyes Adrien had ever seen in his life.

And so began a rather unusual story of a pair of best friends and the cats who brought them together.


	2. Marinette

**2\. Marinette**

MARINETTE DUPAIN-CHENG WAS A GOOD CHILD.

She helped out in her parents' bakery and knew her limits and always did her chores. Maybe it was to be expected, as she had loving parents who doted on her and taught her well. Sure, she was clumsy and had a tendency of knocking things over, but she had the brightest smile on her face and was always ready with a helping hand.

And yet, there was something in her that longed for the night air and the adrenaline coursing through her blood. Something that longed to do something _wrong_ , to feel the thrill of the chase.

She had been walking home from school one afternoon when she stumbled upon a box in an alleyway containing a lone kitten with orange – nearly red – fur and darker spots scattered throughout her tiny body. Perhaps it was a testament as to exactly what kind of child she was when her parents allowed her to keep the kitten even though they lived above a bakery as long as the cat stayed in the apartment.

Tikki and Marinette were inseparable after that. Marinette loved the kitten to bits, even going as far as to sneak the cat to school, although no one ever knew about that.

So when Tikki climbed down from the balcony by way of the fire escape one night, Marinette naturally followed frantically. They ran through the dark streets of Paris – a girl and her cat – and perhaps it was miraculous that nothing happened. Tikki pounced on a fire escape of a building that was connected to a whole lane, and Marinette followed suit, shoes clanging on metal as they raced across rooftops, jumping and sprinting, the cat always one step ahead of the girl.

And then she had run headfirst into _him_ – all big green eyes and floppy blond hair and cheeky grin. He had a cat, she found out. Plagg and Tikki were good friends. He also looked familiar and that was because his face was plastered on the huge billboard just behind them but that didn't change anything in Marinette's eyes.

Instead, that night marked the first of countless of nights spent running and jumping on rooftops, a boy and a girl, just two friends looking for something their normal lives didn't offer.

* * *

MARINETTE DUPAIN-CHENG WAS A FRIENDLY CHILD.

So it wasn't a surprise when she had arrived home one day dragging a boy by his hand. The two had promptly holed themselves in her room, giggling making it through the trapdoor. It wasn't a surprise for Marinette to make friends as easily as some people breathed, nor was it surprising for her to bring them home, but it was surprising when the little blond boy returned day after day, Marinette always meeting him excitedly.

They were best friends, and nothing would ever change that.

There was one night in which Tom and Sabine Dupain-Cheng had ventured up to their daughter's room only to find Adrien and Marinette cuddled up in a nest of blankets and pillows, sleeping soundly. It was a sweet, innocent sight, just two children finding comfort in each other, and yet they had to wake them up, because it _couldn't be right for Adrien to be out this late and could they call his parents?_

It broke their hearts when Marinette had immediately objected loudly, clutching his arm in a vice like grip and pulling him behind her as if to shield him from them. The boy had looked away, an unknown emotion crossing his face, as he explained to them that _no one will me missing me at home, not until they need me anyway, but I'll leave if you want me to._ And perhaps it wasn't entirely morally right, but Adrien had spent that night in their house and many more nights although they were more secretive about it.

It wasn't long after that when Adrien brought Marinette to meet _his_ family. His mother was all right, Marinette supposed, but she didn't like his father. Adrien had explained to her that he wasn't the same at home – more quiet and subdued – and she hadn't really believed that her ball of energy of a friend could be anything like subdued, but that day she found out just how little of his true side he let loose at home.

His father had made some off-handed comment about how _Adrien shouldn't spend his time around girls like her and should stop fooling around and focus more on the family business instead_.

And. Adrien. Exploded.

Marinette had never seen anything like it. It was more than a tantrum. It was pure righteous rage coming out of a little nine-year-old body as he defended her with all his soul, and that _she was the best friend he had ever had and she loved him more than they ever could and he would sooner forget the family business than leave her side_. And apparently, his parents had never seen this side of him either, for they took an actual step back, surveyed him critically as he met their gaze unflinchingly and simply nodded in acknowledgement before walking away.

They never bothered her again.

Adrien Agreste's room was large and full of interesting things like a zip line and arcade games but it lacked the warmth and love Marinette had been subjected to her entire life and for the first time, she truly understood why, exactly, he had chosen to seek shelter in her house. And Marinette might have had a low self-esteem but she had never backed down anything whenever somebody needed her, and she vowed that she would bring some life to that room of his.

That day found themselves racing up the stairs and down the zip line, trash talking each other at the arcade games, trying out and nearly hurting themselves learning to skateboard, and falling asleep on beanbags by his miniature library when they read to each other. At the end of the day, Marinette left, waving to Adrien through his gigantic windows, and taking his home with him, but Adrien couldn't help but feel that she had left some part of home in his room as well.

 _You're my best friend, my human diary, and my other half. You mean the world to me, and I love you._


End file.
